/*!	 synfig/blur.h
**	 Blur Helper Header file
**
**	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
**	Copyright (c) 2012-2013 Carlos López
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifndef __SYNFIG_BLUR_HELPER_H
#define __SYNFIG_BLUR_HELPER_H

#include "vector.h"
#include "surface.h"
#include "progresscallback.h"

class Blur
{
public:
    enum Type {
        BOX				= 0,
        FASTGAUSSIAN	= 1,
        CROSS			= 2,
        GAUSSIAN		= 3,
        DISC			= 4,

        FORCE_DWORD = 0x8fffffff
    };

private:
    synfig::Point size;
    int type;
    synfig::ProgressCallback *cb;

public:
    static synfig::Real get_size_amplifier(int type);

    void set_size(const synfig::Point &x)
    {
        size = x;
    }
    const synfig::Point& get_size() const
    {
        return size;
    }

    void set_type(int x)
    {
        type = x;
    }
    int get_type() const
    {
        return type;
    }

    static synfig::Real get_surface_extra_size_amplifier(int type)
    {
        static const synfig::Real gauss_max_deviation = 1.0 / 512.0;
        static const synfig::Real gauss_size_amplifier = 0.5 * sqrt(-2.0 * log(gauss_max_deviation));

        switch (type) {
        case Blur::DISC:
        case Blur::BOX:
        case Blur::CROSS:
            return 0.5;

        case Blur::FASTGAUSSIAN:
            return 1.0;

        case Blur::GAUSSIAN:
            return gauss_size_amplifier;

        default:
            break;
        }

        return 0.0;
    }

    synfig::Real get_surface_extra_size_amplifier() const
    {
        return get_surface_extra_size_amplifier(get_type());
    }

    synfig::Point get_surface_extra_size() const
    {
        return get_size() * get_surface_extra_size_amplifier();
    }

    void get_surface_extra_size(synfig::Real pixels_per_width_unit, synfig::Real pixels_per_height_unit, int &out_dx, int &out_dy) const
    {
        synfig::Point es = get_surface_extra_size();
        out_dx = (int)ceil(fabs(es[0] * pixels_per_width_unit));
        out_dy = (int)ceil(fabs(es[1] * pixels_per_height_unit));
    }

    void get_surface_expanded_size(synfig::Real pixels_per_width_unit, synfig::Real pixels_per_height_unit, int &width, int &height) const
    {
        int dw, dh;
        get_surface_extra_size(pixels_per_width_unit, pixels_per_height_unit, dw, dh);
        width = width > 0 ? width + 2 * dw : 2 * dw;
        height = height > 0 ? height + 2 * dh : 2 * dh;
    }

    Blur(): type(), cb() {}
    Blur(const synfig::Point &s, int t, synfig::ProgressCallback *callb = 0): size(s), type(t), cb(callb) {}
    Blur(synfig::Real sx, synfig::Real sy, int t, synfig::ProgressCallback *callb = 0): size(sx, sy), type(t), cb(callb) {}

    // Parametric Blur
    synfig::Point operator()(const synfig::Point &p) const;
    synfig::Point operator()(synfig::Real x, synfig::Real y) const;

    // Surface based blur
    //	input surface can be the same as output surface,
    //	though both have to be the same size
    bool operator()(const synfig::Surface &surface, const synfig::Vector &resolution, synfig::Surface &out) const;
    bool operator()(cairo_surface_t *surface, const synfig::Vector &resolution, cairo_surface_t *out) const;

    bool operator()(const etl::surface<float> &surface, const synfig::Vector &resolution, etl::surface<float> &out) const;
};

#endif